Navigation

Motive::not-a-function

Key: Motive::not-a-function

Category: arity · Severity: error

Source: src/diag/hints.nix:868

the motive must be a function from the scrutinee's type into a type, not a bare type or value. Supply a one-argument function whose body lives in some U k.

Example

Hint::Motive::not-a-function means the Motive position uses a non-function where the checker needs a Pi-typed term. The example shows the failing form first, then one way to give the checker the missing structure.

# Bad: an eliminator motive is a bare type.
natElim nat zero succCase n

# Better: make the motive a function from the scrutinee.
natElim (x: nat) zero succCase n

← All diagnostic hints